Exactly.. was it harsh? Sure but sometimes that’s life and I think it gave him a push to stop messing around and as they were saying “breezing” through life. He’s about to graduate so it was time for him to get it together I’m sure this will also give him an opportunity to see things from Dajun perspective too and make amends properly
Hmmm I wouldn't say he was breezing through life per se but it's his way of running away or redirecting his frustration with his family and his feelings by sleeping around and locking himself in piano - it's his way of somewhat getting attention. Regardless of whether he was graduating or not, he just needs to face his mom and brother and stop the people pleasing, rather mom pleasing behaviors he has been doing to fully commit to a genuine relationship, with Dajun or anyone, doesn't necessarily have to be Dajun.
Yes, it's tough that Dajun didn't accept his apology but maybe it's a blessing in disguise. It was the time to finally stand up for himself against his mom and brother. It takes a huge event to finally snap you in to your senses. Hopefully his father grow some balls too to support his son, who is aware they have always been unfair with Uigun.